Method and Device for tamper-proof saving of information data about the production-process using additive manufacturing techniques using blockchain

In the last years, the production of products per additive manufacturing gains more and more market share. Additive man ufacturing or 3D printing is a general term that covers a va riety of processes in which material is joined or solidified under computer control to create a three-dimensional object, with material being added together (such as liquid molecules or powder grains being fused together) , typically layer by layer without casting moulds. Different materials and/or sub strates are possible from plastic to metal. (Wikipedia)

This way of production is particularly advantageous for small lot sizes. One of the key advantages of 3D printing is the ability to produce very complex shapes or geometries.

Counterfeiting of product plagiarism is going to be a major problem. Especially for additive manufacturing a solution is needed to avoid the unauthorized prints of CAM models. The transfer of 3D printing design data for decentralized crea tion of objects is only economically viable, if there are ap propriate security mechanisms in place, that ensure control over who is creating samples of the licensed 3D object by the copyright holder. When it comes to things like medical devic es and aerospace components, plagiarism is a serious issue.

Currently several companies promote the use of blockchains for manufacturing processes to improve the visibility of sup ply chains and to detect counterfeiting products based on these blockchains. This process implies that detailed produc tion information is publicized (especially produced scrap to state a reason for reprinting) . Most manufacturers do not want to publicize such details.

The blockchain technology is seen as a possible solution to build a chain of trust. In the publication "Intellectual Property Protection and Licensing of 3D Print with Blockchain Technology", July 2018, Felix Engelmann, Martin Holland, Christopher Nigischer and Josip Stjepandig, (Ulm University, PROSTEP AG, Darmstadt, Germany; NXP Semiconductors Germany GmbH, Hamburg, Germany), DOI : 10.3233/978-1-61499-898-3-103, 25th ISPE Inc. International Conference on Transdisciplinary Engineering at Modena, a solution is described, where based on smart contracts the customer will order a number of parts, which have to be produced by the manufacturer. The results will be stored based on the blockchain technology as well. This system has the disadvantage that the manufacturer must provide information about produced scrap as well, because he needs an additional order to produce the missing product.

EP 342281 A1 and Stuart Trouton et. al . in "3D opportunity for blockchain", https://dupress.deloitte.co/dup-us- en/focus/3d-opportunity/3d-printing-blockchain-in- manufacturing.html, November 2017, discloses a Blockchain da tabase representing an additive manufacturing process, com prising a plurality of data blocks, wherein some blocks of the blockchain hold data about an additive manufacturing pro cess of a component which is to be manufactured via an addi tive manufacturing device.

An additive manufacturing device configured to implement a distributed ledger system using blockchain technology is also described in US 2018/0173203 Al .

Based on Software systems for production planning like SAP productions orders and the different production steps will be observed and tracked, including incoming and outgoing materi als or products.

Tools like MES (Manufacturing Execution System) or SCADA (Su pervisory Control and Data Acquisition) systems store order and process data for a certain time period. This kind of in formation depends on machine interfaces and on the tools. Normally this kind of information will not be published. This kind of information is customer-specific and stored for in ternal use. Currently archiving of data is managed depending on the tools used for production. A SCADA system provides an archive func tionality to store process data, a MES system stores produc tion data at least for the timeframe which is defined by law. ERP (Enterprise Resource Planning) systems often provide tools to archive production data and related documents but the access to production data is limited.

In addition to this internal information sometimes serial numbers will be engraved or printed on the product to ensure a unique identification key which allows the manufacturer to search for archived order and process information.

To ensure the quality of products, general quality certifica tes will be used like ISO 9001M which implies audits by ex ternal companies. Such certificates guarantee that a certain quality standard of the product is achieved.

As a result, these different steps ensure that the manufac turer is able to track & trace the different production-steps but this kind of information is normally not available to end-customers or 3 ^rcl -party companies to detect counterfeiting products in an easy way.

Blockchain — on the other side - publicizes results of manu facturing processes (including suppliers) in form of chained blocks. In this case the end-customer has the possibility to verify the production company of every part as well as time and location of production.

The invention' s purpose is to provide a procedure to publi cize - as a default - reduced information about the produc tion process (which is configurable by the manufacturer) but allows the end-customer (and of course other entitled par ties) to get access to production data in case of product er rors or suspected counterfeiting without the need to have ac cess to the manufacturing site or data.

The problem will be solved by a method for tamper-proof sav ing of information data about the production-process of a product using additive manufacturing techniques, wherein the production-process comprises process-steps, wherein the pro- cess-steps comprises at least one design step and one print step, wherein the information covering the regarding process- steps are mapped to transaction-blocks, wherein the transac tion blocks are concatenated into a chain of consecutive blocks, wherein there are at least two different types of transaction-blocks contained in the blockchain, with

a first type of transaction-blocks representing one individu al process-step and providing at least one internal link to another predecessor and/or successor transaction-block in the blockchain, and a second type of transaction-blocks (BL) rep resenting an individual process-step which needs external ac cess via an interface and providing one internal link (L3) to and from external information.

In an advantageous version, the transaction-blocks are stored in an ASCII based format.

The information data can be published to a trusted third par ty, e. g. a trust-center, that verifies the identity of every communication partner in any communication processes that participate in the production-process.

In another embodiment, the information stored in the transac tion-block regarding the CAD/CAM design process contains ei ther the information of original CAM models for a 3D print process itself or a link to the information of the original models stored outside the transaction-block.

The stored information data in the trusted third party will be identified by an authorization certificate.

The trusted third party / trust-center can additionally store a history of customers.

Further each product can get a unique ID, based on this unique IDs the trust-center then is capable to chain the rec ords from the different companies which had been involved to build the product. For this purpose, a repository to archive production data as a basis to detect counterfeiting or plagiarism of products is provided, which can be used for the analysis of production data as well. It avoids duplicated data for this purpose.

The invention provides a procedure to describe production da ta in a common readable way (using chained blocks) and pro vide the manufacturer the possibility to define which kind of data to publicize.

Instead of a (distributed) blockchain that manages the pro duction data the invention uses a trust-center to publish this kind of information.

In this case, the results of the steps can be stored in docu ment formats like PDF to ensure that this data will be reada ble for the next 10-30 years.

The invention is shown in more detail in the figures:

Figure 1 shows the production process of the additive manu facturing and the underlying blockchain

Figure 2 shows different kinds of information block used in the blockchain.

The invention is based on the following principles:

1. Within a manufacturing plant, all process steps PI, P2, ..., materials and resources can be tracked und traced in a common way. The system must ensure that production data cannot be modified afterwards (e. g. by use of electronic signatures) . Each step creates a block of information Bl, B2, ... which con tains common information (for example CAD/CAM data, orders) and machine or process step specific information like machine protocols or links to process data. Each block refers to its predecessors and vice versa (linked chain of blocks) as shown in figure 1 for Additive Manufacturing.

Each step will be handled in the same way to support the out sourcing of production steps. In one advantageous embodiment of the invention these blocks can be stored in an ASCII based format (e. g. HTML or XML) to ensure that this kind of information could be interpreted in the next years .

The system differentiates between two kind of blocks:

- blocks which represents process steps and provide inter nally links to other blocks (e. g. get material and/or parts within the factory) and

- blocks which represents interfaces from or to external companies (e. g. to manage incoming materials) or to send parts.

The first blocks representing process steps Bl, ... B6 contain information about different steps, in the example of fused deposition modeling, using metal powder, it could be the fol lowing steps:

- CAD/CAM Process, PI

- Production Order, P2

- Print Process, P3

- Powder Recycling, P4

- Heat Treatment, P5

- Separate Parts, P6.

Using another 3D-printing technology using other material like polymer, these steps might look different.

Figure 2 shows an example for a block B3 representing the step "Print Process". This structure is only exemplary, there is an information about the (printing) machine, the Start- Time, End-Time, substrate used, remaining substrate... etc. Blocks which refer to (external) suppliers or customers can be used to connect blocks across companies. The direction of the connection (in or out) will be stored. To support this feature, these blocks will have a different structure.

Figure 2 further shows an example for the use of (printer- depending) substrates for 3D print jobs. The substrate will be delivered by the printer manufacturer and at least the manufacturer and the order number are stored to establish links L3 to the supplier, represented by block BL, with In formation about Company, Order No etc.. Based on these inter face blocks, it is possible to identify which parts/materials had been used for the manufacturing process and which kind of result had been produced.

2. Each product gets a unique ID, preferably engraved or printed on the product. This ID contains a (advantageously globally unique) identifier for the manufacturer and a unique ID which will be managed by the manufacturer itself. The man ufacturer must ensure that it is not possible to produce products with the same ID multiple times.

3. Based on these blocks of information created during the manufacturing process, product or material data will be pub lished to a trust-center. The kind of published information depends on the demand of the end-customers, legal require ments and the manufacturer itself. At least for each product that will be offered to other customers such a record is pub licized. The trust-center should get information about all production steps to ensure, that this kind of information is available even if the company does not exist anymore. In ad dition, production steps are archived especially if interme diate production steps are used which are not direct related to production orders (e. g. producing of parts for internal storage, mixing of batches, etc.) . Of course, this infor mation must be handled in a secure way and it is not neces sary to hand over all production data.

The original CAM models for a 3D print process, for example, do not have to be transferred to the trust-center, a link to the information (e. g. name, storage area and revision} is sufficient, optional a simplified visualization. To get ac cess to the production data of a product, the end-customer will get a key from the manufacturer (limited to the customer and the ordered product)

The trust-center itself should be allowed to make audits to ensure that the blocks cannot be manipulated by the manufac turer . 4. A trust-center will manage not only a manufacturing plant but also suppliers and companies for the post-processing if needed. Based on the unique IDs the trust-center is capable to chain the records from the different companies which had been involved to build the product.

5. Each company which stores information in a trust-center will be identified by certificates. Other companies are not able to publish information within this trust-center, which means that plants that produce illegal copies of products cannot reuse existing blocks from the original manufacturer.

6. To manage this amount of information within a trust- center, preferably a cloud-based approach should be used.

According to the invention, the system provides several ad vantages :

Support to track & trace and to archive data in a common way is possible.

The use of chained blocks to track & trace production steps further provides a possibility to standardize this kind of information and to establish tools to analyze this data in a common way. The information is no longer spread over several tools and mostly document-driven which is difficult to ana lyze .

Now a common archiving concept is provided. MES systems nor mally do not support archives at all, production orders re main in the database. ERP systems on the other hand archive documents .

In addition, these chained blocks provide the possibility to link this information with existing databases or process ar chives. Details like used CAM models or material specifica tions can be stored as links with a direct access to detailed process data if needed. In this case the manufacturer has to ensure that this information is available at least for the time which is required from legal authorities for archives.

Classic suites for manufacturing intelligence (e. g. SAP, Si- matic IT) copy data from different sources into a relational database to generate "intelligent" KPIs and reports. Such a repository cannot be used for archiving, due to the need to use a certain software tool or even a version of a software tool to read this data. Sometimes it is necessary to archive data at least for a longer period of time and it could not be guaranteed that this kind of software will be available after this long period of time. The use of chained blocks provides a possibility to archive data in a standard ASCII based for mat (using HTML/XML based files) and to use this data for a suite to derive KPIs and reports (e. g. using "classic web- servers or graphs) . For that reason these blocks will be sep arated into a common and a specialized section. The common section will provide general information like process step, assigned machine or working place, starting time and dura tion, etc. The other section will provide specific infor mation like special reports or documents, engineering and ma chine data (or links), etc. In case of standardizing the com mon section, it would be possible to develop tools for ar chiving and analysis of production data which could be used for a variety for customers.

Depending on the size of data or due to security reasons, links to external archives could be provided instead of copy ing this data into the blocks (e.g. 30 CAM models, melt pool data, etc) .

3. It is another advantage of the invention, that due to the modular concept, production steps could be tracked across companies and countries.

A block which is used to identify and check incoming goods will for example store the ID used by the supplier and the internal ID used for this material. Based on the ID of the supplier, the block could be linked to the block of the sup plier which describes the delivery. 4. Avoidance of counterfeiting or plagiarizing of merchan dise .

The following measures further improve the prevention of counterfeiting or plagiarizing of merchandise as far as pos sible :

Identification of manufacturers:

A manufacturer needs a certificate from a trust-center to store his production data. The trust-center ensures that the manufacturer cannot store or modify information which is as signed to another manufacturer / company. Furthermore, the different trust-centers ensure the uniqueness of certificates per manufacturer. As a result, manufacturers which want to counterfeit products in the name of the original manufactur er, must reuse existing production data (and to re-use prod- uct-IDs) .

Identification of customers:

In case of reuse existing production data another feature of this invention disclosure will be used to avoid this kind of illegal copies. End-customers will get access to the (publi cized) production data by the manufacturer. This access needs an identification of the customer (e. g. general passwords which could be copied are not allowed) . Only the original manufacturer can provide this kind of access. As a result, any other manufacturer will be blocked.

In case of a transfer of products to a new owner, the new owner makes a request to the manufacturer to get access to the production data. The trust-center will store a history of customers. Currently the blockchain technology is seen as a possible solution to build a chain of trust. Based on smart contracts the customer will order parts which have to be pro duced by the manufacturer. Results will be stored based on the blockchain technology as well.

This system has the disadvantage that the manufacturer pro vides information about produced items with defects as well, because he needs an additional order to produce the missing product. This could be avoided by using trust-centers. The center will get knowledge about produced items with defects but the customers do not have to be informed. Only in case of product errors or illegal reuse of a scrapped product, access will be given to this kind of information.